With modern angiography systems, it is possible to obtain not only 2-dimensional (2D) fluoroscopic images but, by rotation of a C-arm around the patient, 3-dimensional (3D) CT-like images. For the purpose of intervention planning or navigation, these 3D datasets can be co-registered with the 2D fluoroscopic image. This registration can be used to plan percutaneous puncture procedures, such as needle biopsies. Once registered, 2D fluoroscopic overlay images can be rendered under a given C-arm view angle to provide 3D anatomical information as well as a graphical representation of the interventional plan that can be combined with the live x-ray fluoroscopy image.
Methods are known for utilizing a laser fixed to the C-arm and orientated along the planned path of a needle puncture to orient the actual needle along a desired puncture path so that it intersects a targeted location within the patent. Proper orientation of the laser can require manual adjustment of the patient table and/or a C-arm to ensure that the actual needle path coincides with the “virtual” (i.e., theoretical) laser path. This is because not all theoretical paths may be achievable with a C-arm, since the C-arm may be physically limited in angulation and also may be limited so that it does not collide with the patient or physician. The advantage of laser-based guidance methods, however, is that a biopsy needle can be oriented without exposing the patient or physician to x-ray radiation.
Other methods are known for positioning a needle along a virtual path without the use of a laser fixed to a specific position with respect to the C-arm. Such methods instead utilize x-ray radiation to orient the needle position. To adjust the C-arm so that a needle is correctly oriented along a desired path, the puncture target and the skin entry point—which together define a “path of puncture”—are imaged on top of each other on an x-ray detector to provide a “bull's eye view” that enables appropriate adjustment of the C-arm to achieve a desired puncture path.
There is a need for a system and method that combine the benefits of both types of procedures in a way that minimizes overall radiation exposure to patients and practitioners.